I would definitely look into the school's requirements. I have a normal run of the mill laptop. It works fine. Some of my classmates take notes on their tablets, some type on their laptops, and I take notes on paper. Some of my professors will not allow computers into the classroom. Most of the time I don't even need my computer for school since I am looking at notes or books. However, all of our exams are on the computer, so just having a tablet doesn't work.
If you already have a laptop and it meets your school's requirements, take it and see what others are using. Get an idea of what you want to do for class notes, etc. and buy something new then.